See force for background information. When a forced
hypothesis cannot be established a record is made of that fact and
the proof continues. When the proof succeeds a ``forcing round'' is
undertaken in which the system attempts to prove each of the forced
hypotheses explicitly. However, if the rune(:executable-counterpart immediate-force-modep) is enabled at the
time the hypothesis is forced, then ACL2 does not delay the attempt
to prove that hypothesis but undertakes the attempt more or less
immediately.